using maxmind geoip in spark serialized

I am trying to use the MaxMind GeoIP API for scala-spark which is found https://github.com/snowplow/scala-maxmind-iplookups. I load in the file using standard:

val ipLookups = IpLookups(geoFile = Some("GeoLiteCity.dat"), memCache = false, lruCache = 20000)

I have a basic csv file which I load in that contains time and IP adresses:

val sweek1 = week1.map{line=> IP(parse(line))}.collect{
  case Some(ip) => {
    val ipadress = ipdetect(ip.ip)
    (ip.time, ipadress)
    }
}

The function ipdetect is basically defined by:

def ipdetect(a:String)={
  ipLookups.performLookups(a)._1 match{
    case Some(value) => value.toString
    case _ => "Unknown"
  }
}

When I run this program, it prompt that "Task not serializable". So I read a few posts and there seem to be a few ways around this.

1, a wrapper 2, using SparkContext.addFile (which distribute file across cluster)

but I cannot work out how either one of them works, I tried the wrapper, but I don't know how and where to call it. I tried addFile, but it returns a Unit instead of String, which I assume you will need to somehow pipe the Binary file. So I am not sure about what to do now. Any help is much appreciated

So I have been able to somewhat serialize it by using mapPartitions and iterate over each local partition, but I wonder if there is a more efficient way to do this as I have dataset in the range of millions

Assume that your csv file contains an IP address per line, and for example, you want to map each ip address to a city.

import com.snowplowanalytics.maxmind.iplookups.IpLookups

val geoippath = "path/to/geoip.dat"
val sc = new SparkContext(new SparkConf().setAppName("IP Converter"))
sc.addFile(geoippath)

def parseIP(ip:String, ipLookups: IpLookups): String = {
  val lookupResult = ipLookups.performLookups(ip)
  val city = lookupResult._1.map(_.city).getOrElse(None).getOrElse("")
}

val logs = sc.textFile("path/to/your.csv")
             .mapWith(_ => IpLookups(geoFile = Some(SparkFiles.get("geoip.dat"))))(parseIP)

For other ip transformation, please refer to Scala MaxMind IP Lookups. Furthermore, mapWith seems to be deprecated. Use mapPartitionsWithIndex instead.